Gaseous fuels, such as propane or LP gas, are often used for internal combustion engines in applications such as fork lifts or generators. The advantages in such applications of gaseous fuels over liquid fuels such as gasoline or diesel are well known.
The greatest portion of gaseous engine fuel consumed by industrial users is at engine loads from 20% to 80%. An excess amount of fuel, known as "dirty burn", typically occurs below 20% load at slow speeds. Many of the existing gaseous fuel systems use very light pressure differences to meter fuel at idle and light loads and are adversely affected by fuel contamination (oils that are suspended in the fuel). These systems seem to perform better under rich combustion conditions, which sacrifices to some degree efficiency and the clean burn ability of gaseous fuels.
Thus, there presently exists a need for a gaseous fuel carburetor that provides clean burning and high efficiency under the entire range of engine loads and speeds.